低磷胁迫下小麦根系形态特征及Apase活性  

Morphological characteristics and Apase activity of wheat roots under low phosphorus stress

作　　者：王树鹏 汪军成[1,2] 姚立蓉 孟亚雄[1,2] 李葆春 杨轲 司二静[1,2] 王化俊 马小乐[1,2] 尚勋武 WANG Shupeng;WANG Juncheng;YAO Lirong;MENG Yaxiong;LI Baochun;YANG Ke;SI Erjing;WANG Huajun;MA Xiaole;SHANG Xunwu(Gansu Key Lab of Crop Improvement and Germplasm Enhancement,Lanzhou 730070,China;College of Agronomy,Gansu Agricultural University,Lanzhou 730070,China)

机构地区：[1]甘肃省干旱生境作物学重点实验室,甘肃兰州730070 [2]甘肃农业大学农学院,甘肃兰州730070

出　　处：《甘肃农业大学学报》2021年第5期69-76,共8页Journal of Gansu Agricultural University

基　　金：甘肃省教育厅青年博士基金项目(2021QB-029);甘肃省农业小麦产业体系项目(GARS-01-05);省教育厅高校科研项目(2018D-14);甘肃省科技重大专项计划(17ZD2NA016);甘肃省科技计划项目(1506RJZA014).

摘　　要：【目的】研究低磷胁迫下不同磷效率小麦基因型根系形态特征变化及生理适应机理,为挖掘影响小麦磷素吸收的主要因子和通过根系塑性提高养分利用效率的遗传改良提供科学依据.【方法】以春小麦耐低磷品种(wp-35、wp-72)和磷敏感品种(wp-119)为材料,在水培条件下通过正常磷处理(0.2 mmol/L,CK)和低磷胁迫处理(0.02 mmol/L,-P),研究不同磷素水平对小麦苗期根系形态、根冠比和酸性磷酸酶(Apase)等指标的影响.【结果】低磷胁迫下的wp-35和wp-72的总根长、根表面积和根体积与对照相比无显著差异,而磷敏感品种wp-119在磷素胁迫下14 d后根系的形态特征在低磷处理下显著低于对照.wp-35和wp-72的地上部生物量、根系干质量和整株生物量在处理与对照间无显著变化,而wp-119的地上部生物量在14、21、30 d在低磷处理下显著低于正常磷处理,整株生物量在30 d时显著低于对照.磷胁迫对苗期根冠比的影响研究中,发现从14 d开始,在不同磷素水平和品种间根冠比均达到极显著差异,且wp-119在各处理间均低于wp-35和wp-72;wp-35和wp-72的根冠比在30 d时两处理间均达到显著差异,说明磷素胁迫有利于提高根冠比;对于酸性磷酸酶(Apase)在21,30 d时供试品种均在对照与处理间达到显著差异,且wp-35、wp-72的Apase均大于wp-119.在低磷胁迫下,随着时间的延长对小麦的正常生长有较大影响.主成分分析表明:总根表面积、总根体积、根的干质量、根冠比和根系Apase活性受基因型差异的影响较为明显,主成分1中最大载荷值为根冠比(0.937),主成分2中最大载荷值为地上部干质量(0.798),且主成分1的特征值和贡献率大于主成分2,因此根冠比可首选作为区分不同基因型小麦品种的重要参数.磷敏感品种通过增加总根长,根表面积,根体积,根冠比和根系Apase活性,提高根系的活性效率,以适应低磷胁迫的影响.【结论】磷胁迫�【Objective】Phosphorus is one of the important nutrients that restrict crop growth.The study aimed to explore the change of root morphological characteristics and physiological adaptation mechanism of wheat genotypes with different phosphorus efficiency under low phosphorus stress,providing scientific basis for digging the main factors affecting wheat phosphorus absorption and genetically improving its nutrient utilization efficiency through root plasticity.【Method】The spring wheat varieties tolerant to low phosphorus(wp-35,wp-72)and phosphorus-sensitive varieties(wp-119)were employed as materials,which experienced normal-phosphorus condition(0.2 mmol/L,CK)and low-phosphorus stress(0.02 mmoloL-1,-P),respectively,under hydroponic conditions.Then,the effect of different phosphorus levels on wheat seedling root morphology,root to shoot ratio and acid phosphatase(Apase)was determined.【Result】The total root length,root surface area and root volume of wp-35 and wp-72 under low phosphorus stress did not differ significantly with those of the control,while root system development of the phosphorus-sensitive variety wp-119 were significantly inhibited after 14 days of phosphorus stress compared to the control.The above-ground biomass,root dry weight and whole plant biomass of wp-35 and wp-72 did not change greatly between treatment and the control.For phosphorus-sensitive wp-119,the above-ground biomass at 14 d,21 d,and 30 d under phosphorus stress was significantly lower than the control,and the whole plant biomass was significantly lower than the control at 30 days.The findings on effect of phosphorus stress on the root-to-shoot ratio at seedling stage showed that from 14 days after phosphorus stress on,the root-to-shoot ratio displayed extremely significant differences between two phosphorus levels and among three varieties,and that of wp-119 was lower than wp-35 and wp-72 under each treatment.The root-to-shoot ratio of both wp-35 and wp-72 showed significant difference between two treatments at 30 d after t

关 键 词：磷胁迫 小麦 根系形态 根系酸性磷酸酶活性 

分 类 号：S512.1[农业科学—作物学]